The present invention relates to a speaker for generating sounds by vibrating a diaphragm.
In recent years, there is a tendency to mount small electric parts on a printed circuit board, an electrodynamic speaker for the small electronic instrument is accordingly mounted on the printed circuit board. Such a printed circuit for the portable telephone is used as a signaling device.
Referring to FIGS. 5, 6 and 7, which are a ton plan view of a conventional electrodynamic speaker, a sectional view taken along a line VI—VI of FIG. 5, and a bottom plan view of the sneaker of FIG. 5, respectively, an electrodynamic speaker 50 has a circular frame 51 having a central circular hole 51a and a pair of projection portions 51d. An annular shoulder 51b is formed on the frame 51 and a cylindrical hole 51e is formed in each of the projection Portions 51d. 
A yoke 52 made of magnetic material and having a dish-shape is secured to the wall of the central hole 51a. A disk-shape magnet 53 is secured to the yoke 52 and a disk-shape top plate 54 is securely mounted on the magnet 53. Thus, a magnetic circuit is formed between the yoke 52 and the top plate 54, interposing the magnet 53.
A circular diaphragm 55 made of plastic has a spherical central portion, and a circular recess 55a at the periphery of the central portion. An annular voice coil 56 is fixed to the underside of the recess 55a and inserted in the gap between the periphery of the top plate 54 and an upper portion of the yoke 52.
A pair of lead plates 57, each of which is made of an elongated metal plate, are embedded in the frame 51. An end of each of the lead plates 57 is connected to the voice coil 56, the other end is inserted in the hole 51e of the projection portion 51d. A coil spring 58 is inserted in each hole 51e. An upper end 58a of the coil spring 58 is inserted in a hole formed in an end portion 57a of the lead plate 57 and electrically connected to the lead plate 57 by solder. The lower end of the spring 58 is projected from the underside of the frame 51.
Both ends of the coil 56 are soldered to ends of lead plates 57. Thus, the coil 56 is connected to the coil springs 58.
A cover 59 has sound emanating holes 59a and is adhered to the shoulder 51b. The coil springs 58 are pressed against a circuit pattern on a substrate.
In the conventional speaker, since the projection portions 51d are projected from the frame 51, the speaker occupies a larger area. Thus, the projection prevents the speaker from being miniaturized.